Balkan rivalries cast a shadow over 2016 European Championship qualifying on Tuesday as the match between Serbia and Albania in Belgrade was abandoned after an Albanian flag considered provocative by Serbian fans was flown over the stadium by a drone.

English referee Martin Atkinson interrupted the match in the 41st minute when Serbia defender Stefan Mitrovic managed to grab the banner and Albania players tried to protect it. Several Serbian fans invaded the pitch and clashed with Albania players.

"The Euro 2016 Qualifying match between Serbia and Albania has been abandoned and the circumstances will be reported to the UEFA Disciplinary Body," European football's ruling body said in a statement.

Albanian fans had been warned against attending the game between the two Balkan rivals that have had turbulent relations - mainly over the former ethnic Albanian-dominated Serbian province of Kosovo that declared independence in 2008.

"We wanted to continue the match, but Albanian players said they were not psychologically ready," Serbia captain Branislav Ivanovic said.

Elsewhere, John O'Shea scored in his 100th international for Ireland in the fourth minute of stoppage time to give his side a dramatic 1-1 draw with World Cup holder Germany, which suffered another setback in Group D after losing 2-0 in Poland.

Cristiano Ronaldo also scored in the fourth minute of injury time to give Portugal a 1-0 win over Denmark and put his team's campaign back on track after a stunning 1-0 loss at home to Albania in Group I.